His choice of notes, along with bouncy dynamics, approximated both R&B and jazz - a perfect counterpoint to the ringing guitar patterns and Ringo Starr's swishy hi-hat.

Perhaps more amazing than McCartney's intuitive playing (shifting approaches during the chorus and again in the guitar solo) is that he could do it all - and still does - while singing lead...and not looking at the fretboard. Try that on for size!